penetrable_disk.m

% Class representing penetrable scatterers
%
%   scat = penetrable_disk(k,r,nu) sets up object for a circle with radius r.
%   The wavenumber is k and the refractive index is nu.
%
%   scat.plot() plots the scatterer.
%
%   h = scat.plot() plots the scatterer and returns the handle h of the
%   graphics object.
%
% See also: design, sound_soft_disk, sound_hard_disk, tmatsolver.
%
% Stuart C. Hawkins - 12 January 2023

classdef penetrable_disk < design
    
    properties
        radius
    end

    methods

        %-----------------------------------------------
        % constructor
        %-----------------------------------------------

        function self = penetrable_disk(kwave,radius,name,nu)

            % set default name
            if nargin<3 || isempty(name)
                name = 'penetrable disk';
            end

            % get order for T-matrix using Wiscombe's formula
            n = suggestedorder(kwave,radius);

            % compute the T-matrix
            T = mie_tmatrix(kwave,radius,n,'PENETRABLE',[],nu);

            % call the parent constructor to setup the scatterer
            self = self@design(T,name);

            % radius is stored only in case we want to plot the scatterer
            self.radius = radius;

        end

        %-----------------------------------------------
        % plot function
        %-----------------------------------------------

        function varargout = plot(self)

            % get angles in [0,2*pi] to plot the circle
            theta = linspace(0,2*pi,200);

            % plot the circle
            h = plot(self.radius*cos(theta),self.radius*sin(theta),'k-');

            % return graphics handle if needed
            if nargout>0
                varargout{1} = h;
            end

        end

    end

end